Spectrum analysis is very essential requirement in instrumentation and communication signal interception .Spectrum analysis is normally carried out by online or offline FFT processing. But the FFT being highly mathematical intensive, is not suitable for low area and low power applications. Offline FFT processing can’t give the real time spectrum estimation which is essential in communication signal interception. Online FFT computation takes very high resources, which makes the system costly... Topics: FFT, Goertzel algorithm, Spectrum Analysis, VHDL, XilinX ISE, Modelsim, Spartan 3E-FPGA board.